An NCCAM-funded study that analyzed phone calls to poison control centers found a higher rate of side effects from ephedra, compared with other herbal products.

Other studies and systematic reviews have found an increased risk of heart, psychiatric, and gastrointestinal problems, as well as high blood pressure and stroke, with ephedra use.

According to the US Food and Drug Administration (FDA), there is little evidence of ephedra's effectiveness, except for short-term weight loss. However, the increased risk of heart problems and stroke outweighs any benefits.

In 2004, the FDA banned the US sale of dietary supplements containing ephedra. The FDA found that these supplements had an unreasonable risk of injury or illness - particularly cardiovascular complications - and a risk of death. The ban does not apply to traditional Chinese herbal remedies or to products like herbal teas regulated as conventional foods.*

Between 1995 and 1997, the FDA received more than 900 reports of possible ephedra toxicity. Serious adverse events such as stroke, heart attack, and sudden death were reported in 37 cases.

Using ephedra may worsen many health conditions such as cardiovascular disease, kidney disease, and diabetes.

Ephedra may cause seizures in otherwise healthy people as well as in people with seizure disorders.

Women who are pregnant or breast-feeding and children should avoid taking ephedra.

Ephedra use may lead to serious health problems when used with other dietary supplements or medicines.

Combining ephedra with caffeine increases the risk of potentially serious side effects.

Before taking any new medications, including natural health products, speak to your physician, pharmacist, or other health care provider. Tell your health care provider about any natural health products you may be taking.

*Products regulated as drugs that contain chemically synthesized ephedrine are not dietary supplements and are not covered by this rule. These include drugs used for the short-term treatment of asthma, bronchitis, and allergic reactions.